Reusable water bottles are great, but even with the help of soapy water and a bottle brush, they can be difficult to clean. When you're finished with the brush, fill your reusable bottle with water and pop in a couple of denture cleaning tablets. Let it sit overnight, and the bottle will be as good as new.

You'll still want to follow up with a narrow bottle brush after you come back to your bottle in the morning, just to get the dregs out. Still, the effervescence and cleaning power of the tablets will dislodge things like mineral buildup or mildew and power it away overnight while it works its magic. You can use this same trick for things like tea kettles and coffee pots, wine bottles, drink pitchers, or even the toilet—anything you need to clean that has a small opening that makes it tough to get in there.